Maybe I'm just don't understand how it works, but why can't I get similar power out of similar sized cases ? Pictured below is a 9.3x62, a 375x2-1/2 NE and a 338-06 improved.
Now as the 375 cartridge is of similar size to the 338 one, shouldn't I be able to get similar power?
According to the experts, the 375 is only similar in power to a 375 Win or 35 Rem,if in a strong action like a P14, why wouldn't I be able to get 35 Whelen like performance ?
As for case strength, mine are made from shortened 9.3x74R cases
Please enlighten me!




Roger

The double rifle cartridges were designed for much lower pressures. If I understand correctly the 9.3X74R is designed for less than 35000 cup pressure while the 9.3X62 is a 48000 cup cartridge. The 338 is a 54000 cup cartridge.

ASSUMING SIMILAR CASE CAPACITY, Now in a strong single shot like a Ruger No1 you can shoot similar pressure loads if the brass will hold up to it. the brass is the weakest link in this case.

The other thing is bullet diameter. With similar case capacity & pressures, you cannot get same velocity for equal bullet weight with different diameters. For example in a Ruger No1 action, if you selected 250 gr bullets for all three calibers, theoretically the largest caliber will give you best velocity & the smaller calibers will give you less velocity for same pressure levels. This is pure physics - something to do with expansion ratios.....

The other issue for me personally is that the old classics are just that - classics. My Mannlicher Schoenauer 9.5X57MS (375 MS) will do 2200 fps with 270 gr bullets. The same cartridge in a Mauser action can be loaded to 2500 fps. But then it is Classic Mannlicher Schoenauer & not a Classic Mauser cartridge. So I load my 9.3X62 to full potential of 2400 fps with 286 gr bullets in my Simson Mauser 98 rifle (almost 100 years old rifle!)

JMTBW

Equal volume should be close to equal velocity AT EQUAL PRESSURE. A 9.3x74 case is normally loaded to 49,000 the others in the range of 60000. Yes a p14 can handle that pressure can a 74 case? That I can't answer.

QL says the difference in velocity in a 375 Whelen between 49&60,000psi with a 260gr is about 210fps.

Give me your case dimension, capacity, oal, bullet and pressure and I'd be happy to run QL for you.

quote:

the brass is the weakest link in this case.

In theory, GIVEN THE CAPABILITY OF BEING LOADED TO EQUAL PRESSURE, I believe that with equal weight bullets the 375 will give the highest muzzle velocity as the base area of the bullet is the greatest of the three.

However down range the 338-06 will retain that velocity better and shoot flatter having the best ballistic properties of the three.

The 375 x 2 1/2" having the worst ballistic properties of the three will have the worst down range retained velocity and muzzle energy.

Compared to the two smaller calibres the 375 will drop like a stone and shed velocity and energy by at least a factor of 1.25 to 1.

As a compromise between the three the 9.3 x 62 in say 250 grain bullet will be the best overall performer.

Having a larger base area than the 338-06 it will give the same muzzle velocity as the 338-06 (assuming identical weight bullets) with less pressure.

Yet will shoot flatter and have better retained one hundred yards velocity and therefore energy than the 375 x 2 1/2.

Which may explain its continuing popularity and why the 375 x 2 1/2" even in rimless form (aka Nakihunters 375 MS or today's 375 Whelen) is in 2010 a "dead duck".

Thanks for all your input. I was possibly being a bit unclear in my intentions of this question, I was not looking for a comparison between these three cartridges ( the picture was merely for size comparison ) but an answer as to why the 375 2 1/2 NE was,theoretically, no more powerful than 375 win. or 35 Rem. even in a strong action. Surely case capacity alone would give it a greater margin.As for downrange ballistics, I'm only looking for a 200 yard max. with possible use on water buff and sambar. I'm not looking for an elephant gun, but at least something better than what the "experts " think of this round.
My choice of this cartridge was for its " classic " appeal in a classic action.

Roger

Like I said give me the data and I'll run it for you. Simply increasing the volume by the ration of the case length using all other 375W data gave 3-400fps more velocity. Or a 260gr Nosler Accubond at 2375+/- As I said my question is can the 74 case handle the extra pressure?

quote:

Originally posted by yumastepside:
Thanks for all your input. I was possibly being a bit unclear in my intentions of this question, I was not looking for a comparison between these three cartridges ( the picture was merely for size comparison ) but an answer as to why the 375 2 1/2 NE was,theoretically, no more powerful than 375 win. or 35 Rem. even in a strong action. Surely case capacity alone would give it a greater margin.As for downrange ballistics, I'm only looking for a 200 yard max. with possible use on water buff and sambar. I'm not looking for an elephant gun, but at least something better than what the "experts " think of this round.
My choice of this cartridge was for its " classic " appeal in a classic action.

Roger

The answer lies in the action of the rifle that the cartridge was designed for. The 375 rimmed NE double rifle was designed for less than 35000 cups of pressure while the 375 MS rimless was also designed for less than 45000 cup while the other cartridges were designed for Mauser 98 or more modern rifles and therefore could handle 50,000 cup to 55,000 cup.

Sorry Nakihunter, I can't agree with that (the action it was designed for limits the cartridge ) , look at what can be done with cases like the 7x57 or 7x57 improved in a modern action, or even ones like a 45-70 in a No. 1 Ruger

Roger

I a strong action then your 375 x 2 1/2" would be capable of higher velocity than a 375 Winchester. Why? Because it has a longer case and greater powder capacity.

Compare 38 Special with 357 Magnum. However eventually no matter how long the case there comes a point where that extra length (and powder capacity) gives less and less of a benefit.

So 357 Maximum is not that much more than 357 Magnum.

Taken to its extreme I doubt that in any strength action - even one built as thick as a field gun - that a 375 x 6" (in other words a 375 with a six inch long case) would be really twice as powerful as your 375 x 2 1/2".

It is something to do with the internal diameter of the case and how that affects the burn rate of the powder.

In other words if you want faster velocity you increase the diameter of the case and not the length of the case.